Mandrel for electrode assemblies

ABSTRACT

A mandrel for use in a battery assembly may include a positive mandrel portion and a negative mandrel portion. Each of the mandrel portions may include a connector element coupling region and an electrode coupling region. The connector element coupling region may be configured to be coupled to a connector element and the electrode coupling region may be configured to be coupled to an electrode.

The disclosure herein relates to mandrels for electrode assemblies andfor methods of providing such mandrels and electrode assemblies.

Batteries for medical devices, such as implantable medical devices, havedemanding requirements. For example, such requirements may include longlife, high-power output, low self-discharge rate, compact size, and highreliability. Further, the need for miniaturization while maintaining, orincreasing, power output may result in the elimination of dead spacewithin a battery. The elimination of dead space, however, may result ina greater difficulty of assembly due to the increasingly small size ofcomponents.

Traditionally, coiled battery assemblies have been produced by couplingelectrodes to a mandrel (e.g., wrapping around). Once coupled, themandrel may be removed providing a coiled electrode assembly for use ina battery. The removal of the mandrel from the core of the coiledelectrode assembly may potentially damage the electrode assembly (e.g.,the core of the coiled electrode assembly may be pulled out with theremoval of the mandrel).

Further, coiled electrode assemblies have been produced by couplingelectrodes around rod-shaped, non-conductive, and/or non-deformablecores. Conductive tabs may be added to each electrode and may be usedfor electrical connection outside of the battery.

SUMMARY

Generally, the disclosure herein describes mandrels for use in electrodeassemblies that include a connector element coupling region and anelectrode coupling region. Such electrode assemblies may be used inbatteries for implantable medical devices. The connector elementcoupling region may be configured for coupling a connector element suchas, e.g., a feedthrough pin, to the mandrel, and the electrode couplingregion may be configured for coupling an electrode to the mandrel. Theconnector element coupling region and the electrode coupling region maybe electrically coupled such that a connector element coupled to theconnector element coupling region may be electrically coupled to anelectrode coupled to the electrode coupling region. The connectorelement coupling and electrode coupling regions may each include one ormore materials selected to provide effective coupling (e.g., mechanicalcoupling, electrical coupling, etc.) to a connector element and anelectrode, respectively. In at least one embodiment, the connectorelement coupling region may include at least one material that is alsoincluded in the connector element to be coupled thereto, and theelectrode coupling region may include at least one material that is alsoincluded in the electrode to be coupled thereto.

Connector elements may include different material than electrodes. Forexample, a connector element may include titanium while an electrode mayinclude aluminum. As such, in this example, the connector elementcoupling region may include titanium and the electrode coupling regionmay include aluminum. Generally, the connector element coupling regionmay include a different material than the electrode coupling region. Inother words, the connector element coupling region may include a firstmaterial and the electrode coupling region may include a second materialthat is different than the first material.

One exemplary mandrel for an electrode assembly (e.g., to be used in abattery of an implantable medical device) may include a positive mandrelportion a negative mandrel portion. The positive mandrel portion mayinclude a connector element coupling region and an electrode couplingregion. The connector element coupling region may be configured forcoupling the positive mandrel portion to a connector element and mayinclude a first conductive material (e.g., titanium). The electrodecoupling region may be electrically coupled to the connector elementcoupling region and may be configured for coupling the positive mandrelportion to an electrode. The electrode coupling region may include asecond conductive material (e.g., aluminum) different than the firstconductive material.

The negative mandrel portion of the exemplary mandrel may be spacedapart from the positive mandrel portion and may include a connectorelement coupling region and an electrode coupling region. The connectorelement coupling region may be configured for coupling the negativemandrel portion to a connector element and may include a firstconductive material (e.g., titanium). The electrode coupling region maybe electrically coupled to the connector element coupling region and maybe configured for coupling the negative mandrel portion to an electrode.The electrode coupling region may include a second conductive material(e.g., aluminum) different than the first conductive material. In atleast one embodiment, the second conductive material of the electrodecoupling region of the positive mandrel portion is different than thesecond conductive material of the electrode coupling region of thenegative mandrel portion.

In one or more exemplary mandrels, for at least one of the positivemandrel portion and the negative mandrel portion, at least a portion ofthe electrode coupling region may be positioned adjacent to at least aportion of the connector element coupling region to mechanically couplethe connector element coupling region and the electrode coupling region.In at least one embodiment, for at least one of the positive mandrelportion and the negative mandrel portion, the connector element couplingregion may define a mating region (e.g. an opening) configured to matewith a mating region defined by at least a portion of the electrodecoupling region to mechanically couple the connector element couplingregion and the electrode coupling region.

In one or more exemplary mandrels, the electrode coupling region for atleast one of the positive mandrel portion and the negative mandrelportion is formed by depositing the second conductive material. In atleast one embodiment, for at least one of the positive mandrel portionand the negative mandrel portion, the connector element coupling regionmay define a connector element channel configured for receiving aconnector element to be coupled therein, and the electrode couplingregion may include at least a planar surface for coupling an electrodethereto. In at least one embodiment, the mandrel may further include aremovable portion removably coupled to both of the positive mandrelportion and the negative mandrel portion. In at least one embodiment,for at least one of the positive mandrel portion and the negativemandrel portion, the connector element may include the first conductivematerial and the electrode may include the second conductive material.

One exemplary mandrel for an electrode assembly (e.g., to be used in abattery of an implantable medical device) may include a positive mandrelportion and a negative mandrel portion spaced apart from the positivemandrel portion. At least one of the positive mandrel portion and thenegative mandrel portion may include a primary portion and an electrodecoupling portion. The primary portion may include a first conductivematerial (e.g., titanium). The electrode coupling portion may beelectrically coupled to the primary portion and may include a secondconductive material (e.g., aluminum) different than the first conductivematerial. Further, the electrode coupling portion may define anelectrode coupling region configured for coupling to an electrode. In atleast one embodiment, the electrode may include the second conductivematerial.

In one or more exemplary mandrels, the electrode coupling region mayinclude at least a planar surface on the electrode coupling portion forcoupling an electrode thereto. In at least one embodiment, the electrodecoupling region may define at least one coupling protrusion on theelectrode coupling portion for coupling an electrode thereto.

In one or more exemplary mandrels, the primary portion may define aconnector element region configured for coupling to a connector element.In at least one embodiment, the connector element region may define aconnector element channel configured for receiving a connector elementto be coupled therein.

In one or more exemplary mandrels, the primary portion may define amating region configured to mate with a mating region defined by atleast a portion of the electrode coupling portion to mechanically couplethe primary portion and the electrode coupling portion. In at least oneembodiment, the mating region of the primary portion may define anopening configured to receive at least a portion of the mating region ofthe electrode coupling portion.

In one or more exemplary mandrels, the electrode coupling portion may beformed by depositing the second conductive material onto a depositionregion of the primary portion. In at least one embodiment, the mandrelfurther may include a removable portion removably coupled to both of thepositive mandrel portion and the negative mandrel portion.

One exemplary mandrel for an electrode assembly (e.g., to be used in abattery of an implantable medical device) may include a positive mandrelportion and a negative mandrel portion spaced apart from the positivemandrel portion. At least one of the positive mandrel portion and thenegative mandrel portion may include a primary portion and a connectorelement coupling portion. The primary portion may include a firstconductive material (e.g., aluminum). The connector element couplingportion may be electrically coupled to the primary portion and mayinclude a second conductive material (e.g., titanium) different than thefirst conductive material. The connector element coupling portion maydefine a connector element coupling region configured for coupling to aconnector element. In at least one embodiment, the connector element mayinclude the second conductive material.

In one or more exemplary mandrels, the connector element coupling regionmay define a connector element channel configured for receiving aconnector element to be coupled therein. In at least one embodiment, theprimary portion may define a mating region configured to mate with amating region (e.g., an opening) defined by at least a portion of theconnector element coupling portion to mechanically couple the primaryportion and the connector element coupling portion.

In one or more exemplary mandrels, the connector element couplingportion may be formed by depositing the second conductive material ontoa deposition region of the primary portion. In at least one embodiment,the primary portion may define an electrode coupling region, and theelectrode coupling region may include at least a planar surface on theprimary portion for coupling an electrode thereto.

The above summary is not intended to describe each embodiment or everyimplementation of the present disclosure. A more complete understandingwill become apparent and appreciated by referring to the followingdetailed description and claims taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an exemplary electrode assembly.

FIGS. 2A-2B are front and cross sectional views, respectively, of anexemplary mandrel of the electrode assembly of FIG. 1.

FIG. 3 is a front view of the mandrel of FIGS. 1-2 with electrodesattached thereto.

FIG. 4 is an end view of an exemplary coiled electrode assembly usingthe mandrel of FIGS. 1-3.

FIGS. 5A-5B are front views of exemplary battery assemblies using thecoiled electrode assembly of FIG. 4.

FIG. 6A is a perspective view of an exemplary mandrel for an electrodeassembly including positive and negative mandrel portions, eachincluding an electrode coupling portion.

FIG. 6B is a perspective, exploded view of the mandrel of FIG. 6A.

FIG. 6C is a plan view of the mandrel of FIGS. 6A-6B.

FIG. 6D is a cross sectional view of the mandrel of FIGS. 6A-6C.

FIG. 7A is a perspective view of an exemplary mandrel for an electrodeassembly including positive and negative mandrel portions, eachincluding an electrode coupling portion.

FIG. 7B is a perspective, exploded view of the mandrel of FIG. 7A.

FIG. 7C is a plan view of the mandrel of FIGS. 7A-7B.

FIG. 7D is a cross sectional view of the mandrel of FIGS. 7A-7C.

FIG. 8A is a perspective view of an exemplary mandrel for an electrodeassembly including positive and negative mandrel portions, eachincluding an electrode coupling portion formed by deposition.

FIG. 8B is a cross sectional view of the mandrel of FIG. 8A.

FIG. 9A is a perspective view of an exemplary mandrel for an electrodeassembly including positive and negative mandrel portions, eachincluding a connector element coupling portion.

FIG. 9B is a perspective, exploded view of the mandrel of FIG. 9A.

FIG. 9C is a cross sectional view of the mandrel of FIGS. 9A-9B.

FIG. 10A is a perspective view of an exemplary mandrel for an electrodeassembly including positive and negative mandrel portions, eachincluding a connector element coupling portion and an electrode couplingportion.

FIG. 10B is a cross sectional view of the mandrel of FIG. 10A.

FIG. 11 is a block diagram of an exemplary method of producing anexemplary mandrel, e.g., the mandrel of FIGS. 10A-10B.

FIGS. 12A-12D are perspective views of portions of the exemplary mandrelof FIGS. 10A-10B being produced.

FIG. 13A is a perspective view of an exemplary mandrel for an electrodeassembly including positive and negative mandrel portions, eachincluding a connector element coupling portion and an electrode couplingportion.

FIG. 13B is a perspective view of the mandrel of FIG. 13A with connectorelements coupled thereto.

FIG. 13C is a front view of the mandrel of FIGS. 13A-13B.

FIG. 13D is a rear view of the mandrel of FIGS. 13A-13C.

FIG. 13E is an end view of the mandrel of FIGS. 13A-13D.

FIG. 14 is a perspective view of an exemplary connector element.

FIG. 15A is a front view of an exemplary mandrel for an electrodeassembly including positive and negative mandrel portions, eachincluding a connector element coupling portion and an electrode couplingportion.

FIG. 15B is a rear view of the mandrel of FIG. 15A.

FIG. 15C is a perspective view of the mandrel of FIGS. 15A-15B.

FIG. 15D is a cross sectional view of an exemplary negative mandrelportion of the mandrel of FIGS. 15A-15C.

FIG. 16A is a front view of an exemplary connector element couplingportion of the negative mandrel portion of the mandrel of FIGS. 15A-15D.

FIG. 16B is a perspective view of the connector element coupling portionof FIG. 16A.

FIG. 17A is a front view of an exemplary electrode coupling portion ofthe negative mandrel portion of the mandrel of FIGS. 15A-15D.

FIG. 17B is a perspective view of the electrode coupling portion of FIG.17A.

FIG. 18A is a perspective view of an exemplary mandrel for an electrodeassembly including positive and negative mandrel portions, eachincluding a connector element coupling portion and an electrode couplingportion.

FIG. 18B is a front view of the mandrel of FIG. 18A.

FIG. 18C is a rear view of the mandrel of FIGS. 18A-18B.

FIG. 18D is a cross sectional view of an exemplary positive mandrelportion of the mandrel of FIGS. 18A-18C.

FIG. 19 is a perspective view an exemplary connector element couplingportion of the mandrel of FIGS. 18A-18D.

FIG. 20 is a perspective view an exemplary electrode coupling portion ofthe mandrel of FIGS. 18A-18D.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description of illustrative embodiments,reference is made to the accompanying figures of the drawing which forma part hereof, and in which are shown, by way of illustration, specificembodiments which may be practiced. It is to be understood that otherembodiments may be utilized and structural changes may be made withoutdeparting from (e.g., still falling within) the scope of the disclosurepresented hereby.

Exemplary apparatus and methods shall be described with reference toFIGS. 1-20. It will be apparent to one skilled in the art that elementsor processes from one embodiment may be used in combination withelements or processes of the other embodiments, and that the possibleembodiments of such apparatus and methods using combinations of featuresset forth herein is not limited to the specific embodiments shown in theFigures and/or described herein. Further, it will be recognized that theembodiments described herein may include many elements that are notnecessarily shown to scale. Still further, it will be recognized thattiming of the processes and the size and shape of various elementsherein may be modified but still fall within the scope of the presentdisclosure, although certain timings, one or more shapes and/or sizes,or types of elements, may be advantageous over others.

As used herein, the term “mandrel” may refer to at least a portion of aninterior core of an electrode assembly upon which one or more electrodesmay be wound. Further, the term “mechanically coupled” may refer to aconnection between elements, or portions, that resists separationbetween such elements when faced with ordinary forces that occur duringthe typical usage of electrode assemblies. Further, the term“electrically coupled” may refer to a conductive connection betweenelectrical components that effectively conducts electricitytherebetween. In addition, the term “electrode” may refer to anelectrode substrate that can be coated with an active material, e.g.,for use in a coiled battery assembly. In at least one embodiment, anelectrode may include a substrate in the form of a strip of thinconductive material such as a foil.

The disclosure herein relates to mandrels for electrode assemblies andfor methods of providing such mandrels and electrode assemblies. Morespecifically, such mandrels may include a positive mandrel portion and anegative mandrel portion, each portion defining an electrode couplingregion for coupling to an electrode and a connector element couplingregion for coupling to a connector element (e.g., such as a feedthroughpin). To define such electrode coupling and connector element couplingregions, the positive and negative mandrel portions may utilize one ormore portions, materials, structures, etc. as will be described hereinwith reference to FIGS. 6-20. A general exemplary electrode assemblyincluding a mandrel is described herein with reference to FIGS. 1-5 to,e.g., provide a descriptive reference example.

An electrode assembly 16 including a mandrel 20 having a positivemandrel portion 22 and a negative mandrel portion 24 (e.g., conductiveportions) is illustrated in FIG. 1. The electrode assembly 16 furtherincludes positive and negative electrodes 30, 32 and positive andnegative connector elements 42, 44. In this example, the positiveconnector element 42 is a positive feedthrough pin (e.g., elongated andhaving a circular cross section) and the negative connector element 44is a negative feedthrough pin (e.g., elongated and having a circularcross section). Although the connector elements 42, 44 are feedthroughpins in this and other embodiments described herein, exemplary connectorelements 42, 44 may be any element configured to be coupled to, or partof (e.g., integral with), the positive and negative mandrel portions 22,24 of the mandrel 20 and configured to conduct electricity from thepositive and negative mandrel portions 22, 24 to outside of a batterycasing that the electrode assembly 16 may be located within. In at leastone embodiment, the connector elements 42, 44 may be elongated portions(e.g., a tabs, etc.) extending from each of the positive and negativemandrel portions 22, 24. In at least one embodiment, the connectorelements may be rods having various cross sectional shapes (e.g.,rectangular cross section, oblong cross section, etc.). In at least oneembodiment, the connector elements may be sheet-like material similar tothe electrodes 30, 32.

As shown, the electrode assembly 16 may be described as being orientedalong an axis 8. For example, as shown, the connector elements 42, 44(and the channels 23, 25 within which the connector elements 42, 44 arelocated as labeled in FIGS. 2A-2B) are parallel to the axis 8. Further,the mandrel 20 may be configured to be rotated about the axis 8 to wind,or wrap, the electrodes 30, 32 around the mandrel 20 to form a coiledbattery assembly (as shown in FIG. 4).

The positive electrode 30 and the negative electrode 32 may be coupled(e.g., electrically coupled, mechanically coupled, bonded, etc.) to themandrel 20. More specifically, the positive electrode 30 may beelectrically and mechanically coupled to the positive mandrel portion 22and the negative electrode 32 may be electrically and mechanicallycoupled to the negative mandrel portion 24. As illustrated, the positiveelectrode 30 and the negative electrode 32 may be coupled to the mandrel20 on opposite faces (or sides) while the connector elements 42, 44 maybe coupled on the same face (or side) of the mandrel 20. In at least oneembodiment, the positive electrode 30 and the negative electrode 32 maybe coupled to the mandrel 20 on the same face (or side). In at least oneembodiment, the connector elements 42, 44 may be coupled to the mandrel20 on opposite faces (or sides).

As shown, the positive electrode 30 and the negative electrode 32 can beelectrically coupled to the mandrel portions 22, 24, respectively, bywelding the electrodes 30, 32 to a flat, or planar, surface of themandrel portions 22, 24 of the mandrel 20 (see FIG. 3) as furtherdescribed herein. Further, a separator (not depicted) can be located(e.g., placed, interwoven, etc.) between the positive and negativemandrel portions 22, 24 of the mandrel 20 through passage “p” labeled inFIGS. 2A-2B to, e.g., electrically isolate, or insulate, the positivemandrel portion 22 from the negative mandrel portion 24 when theelectrode assembly 16 is assembled into a battery. The separator may becoupled or not coupled to the mandrel 20.

The mandrel 20 may further include removable portion 26 and may define adecoupling region 28 configured to assist the removal of the removableportion 26 from the positive and negative mandrel portions 22, 24, e.g.,after the electrode assembly 16 has been located within a batterycasing, after the electrode assembly 16 has been produced, etc. As usedherein, a “removable portion” may refer to a portion of the mandrel 20that can be detached from the remainder of the mandrel 20. In at leastthe embodiment depicted, the decoupling region 28 may include adepression 29 that is formed (e.g., scored, molded, stamped, etc.)between the removable portion 26 and the remainder of the mandrel 20 toallow the removable portion to be removed from the remainder of themandrel 20. In at least one embodiment, the removable portion 26 may bedetached, or decoupled, by snapping, cutting, breaking, tearing, and/orclipping the removable portion 26 from the remainder of the mandrel 20.

The depression 29 (e.g., a channel, groove, etc.) may extend across themandrel 20 perpendicular to the axis 8 and between the mandrel portions22, 24 and the removable portion 26. As such, the removable portion 26may be removed (e.g., “broken off”) from the positive and negativemandrel portions 22, 24 by holding the positive and negative mandrelportions 22, 24 stationary and rotating the removable portion 26 aboutan axis (e.g., an axis perpendicular to the axis 8) defined by thedepression 29.

Although the depression 29 is depicted in one or more embodimentsdescribed herein, it is to be understood that the exemplary mandrelsdescribed herein may include any one or more features or elements in thedecoupling region 28 different than the depression 29 that areconfigured to assist the removal of the removable portion 26 from thepositive and negative mandrel portions 22, 24. For example, thedecoupling region 28 may include a perforation, a thinned region,weakened region, tabs, balls, isolated geometric decoupling features,cones, pins, rods, etc., which may be configured to assist in theremoval of the removable portion 26 from the positive and negativemandrel portions 22, 24. Further, in at least one embodiment, no featureor element may be included, or defined, in the mandrel 20 in thedecoupling region 28. In this example, the removable portion 26 may beremoved from the positive and negative mandrel portions 22, 24 byremoving material (e.g., cutting) between (e.g., using a laser, saw,etc.) the removable portion 26 and the positive and negative mandrelportions 22, 24.

While the exemplary mandrels described herein can be made using anyappropriate process, an exemplary mandrel can be made using electricdischarge machining (EDM). Alternatively, an exemplary mandrel can bemade by metal extrusion or by injection molding depending on the needsof the battery and the composition of the mandrel. Further, an exemplarymandrel can be formed using one or more progressive stamping processes.Still further, the regions, channels, grooves, etc. formed in theexemplary mandrels (e.g., for receiving connector elements, for formingthe decoupling region, or for any other feature or element) can be made,produced, or formed, by machining, etching, stamping, cutting, welding,extruding, electromagnetic forming, hot isostatic processing, thermalmechanical or thermomechanical forming, hydro mechanical forming, and/orany other method.

The width 4 of the mandrel 20 (as shown in FIG. 2A) may be greater thanor equal to about 0.1 inches, about 0.2 inches, about 0.25 inches, about0.3 inches, etc. Further, the width 4 of the mandrel 20 may be less thanor equal to about 0.35 inches, about 0.4 inches, about 0.45 inches,about 0.5 inches, about 0.6 inches, etc. The length 6 of the mandrel 20(as shown in FIG. 2A) may be greater than or equal to about 0.4 inches,about 0.5 inches, about 0.6 inches, about 0.7 inches, etc. Further, thelength 6 of the mandrel 20 may be less than or equal to about 0.75inches, about 0.8 inches, about 0.85 inches, about 0.95 inches, about1.0 inches, about 1.25 inches, about 1.25 inches, etc. The thickness 5of the mandrel 20 (as shown in FIG. 2B) may be greater than or equal toabout 0.005 inches, about 0.01 inches, about 0.015 inches, about 0.02inches, etc. Further, the thickness 5 of exemplary mandrel 20 may beless than or equal to about 0.025 inches, about 0.03 inches, about 0.04inches, about 0.045 inches, about 0.05 inches, about 0.06 inches, etc.

In the embodiment depicted, channels 23, 25 (e.g., coupling regions) forreceiving the connector elements 42, 44 (e.g., positive and negativefeedthrough pins, etc.) may be formed in the positive and negativemandrel portions 22, 24, respectively, of the mandrel 20. Although thechannels 23, 25 as shown are both on the same face (or side) of themandrel 20, in other embodiments, the channels 23, 25 may be on oppositefaces. It is to be understood that the channels 23, 25 (e.g., grooves,etc.) may be appropriately sized and/or shaped to accommodate variousshapes and sizes of connector elements 42, 44. For example, the channels23, 25, can be in the shape of a “V,” a rounded groove, a squarebottomed groove, a “C,” a half hex, a beveled square bottomed groove, adovetail groove, etc. Further, the channels 23, 25 may be sized to beslightly smaller than the connector elements to be received therein soas to form an interference fit if the connector elements 42, 44 werepressed or forced into the channels 23, 25.

The electrodes 30, 32 may also vary in size, shape, and length. In atleast one embodiment, the electrodes 30, 32 may be a foil or other thinmalleable conductive substrate (e.g., a grid, expanded metal, mesh,etc.). In at least one embodiment, the foil can be in the form of ametal foil such as, for example, aluminum, steel, silver, copper,nickel, titanium, vanadium, and/or combinations or alloys thereof.

The length of the electrodes 30, 32 (e.g., when the electrodes areunrolled) may be greater than or equal to about 1 inch, about 2 inches,about 3 inches, about 4 inches, about 5 inches, about 6 inches, etc.Further, the length of the electrodes 30, 32 may be less than or equalto about 8 inches, about 10 inches, about 14 inches, about 16 inches,about 18 inches, about 20 inches, about 24 inches, etc. The width of theelectrodes 30, 32 may be greater than or equal to about 0.05 inches,about 0.1 inches, about 0.2 inches, about 0.3 inches, about 0.5 inches,about 0.6 inches, about 0.75 inches, etc. Further, the width of theelectrodes 30, 32 may be less than or equal to about 1 inch, 1.25inches, etc. The thickness of the electrodes 30, 32 may be greater thanor equal to about 0.002 inches, about 0.003 inches, about 0.004 inches,about 0.005 inches, about 0.008 inches, etc. Further, the thickness ofthe electrodes 30, 32 may be less than or equal to about 0.01 inches,about 0.015 inches, about 0.02 inches, about 0.025 inches, about 0.03inches, about 0.04 inches, about 0.05 inches, etc. Also, the electrodes30, 32 can vary in composition depending on the battery chemistry beingused as described further herein.

Separator material, e.g., used to separate the electrodes 30, 32 whenrolled around the mandrel 20, can be any non-conductive material such aspolyethylene, polypropylene and layered combinations thereof. Exemplaryseparators (e.g., made of separator material) generally have a largerwidth and length than the electrodes they cover so as, e.g., to fullyencase the electrodes. Generally, a separator can be sized to extendbeyond a bottom portion of positive and negative mandrel portions 22, 24after removal of removable portion 26 (e.g., to provide additionalinsulation towards the bottom portion of the mandrel portions 22, 24).Exemplary separators may be described in U.S. Patent ApplicationPublication No. 2011/0250481 A1 published on Oct. 13, 2011 and entitled“COIL SEAL TO SECURE THE ELECTRODE WINDINGS OF AN ELECTROCHEMICAL CELL,”which is incorporated herein by reference in its entirety. The separatormaterial may be coupled or uncoupled to the mandrel 20, e.g., prior tolocating the separator material between the electrodes 30, 32 when theelectrodes 30, 32 are being located about, or around the mandrel 20. Inat least one embodiment, the separator material may be passed throughthe passage “p” (e.g., without coupling the separator material to themandrel 20) and extended such that it will separate the electrodes 30,32 from each other when the mandrel 20 is rotated to locate theelectrodes thereon (e.g., held by tension).

Connector elements 42, 44, (e.g., feedthrough pins) can be sized to fitwithin the channels 23, 25, or grooves, defined in the mandrel 20 andcan be made of any electrically conductive material. For example,connector elements may include (e.g., be formed of) steel, platinum,aluminum, titanium, nickel, copper, tantalum, niobium, etc. and/orcombinations or alloys thereof such as, e.g., titanium alloy such asgrade 5 or grade 23, platinum-iridium such as 90 percent platinum/10percent iridium, aluminum sleeve or shell over a titanium core,stainless steel, clad materials, coated materials (e.g., dipped orsprayed), etc. The length of the connector elements 42, 44 may begreater than or equal to about 0.1 inches, about 0.2 inches, about 0.3inches, about 0.4 inches, about 0.5 inches, about 0.6 inches, etc.Further, the length of the connector elements may be less than or equalto about 0.7 inches, about 0.75 inches, about 0.8 inches, about 1 inch,about 1.5 inches, etc. The diameter of the connector elements 42, 44 maybe greater than or equal to about 0.01 inches, about 0.025 inches, about0.05 inches, etc. Further, the diameter of the connector elements 42, 44may be less than or equal to about 0.075 inches, about 0.1 inches, about0.2 inches, etc. Further, the portions of the connector elements 42, 44that extend outside of the battery case after the electrode assembly hasbeen inserted into a battery case may be cut to length.

The exemplary mandrel 20 of FIG. 1 is further illustrated in FIGS. 2A-2Bwithout the remainder of the electrode assembly 16. More specifically, afront view of the mandrel 20 is depicted in FIG. 2A and a crosssectional view of the mandrel 20 taken across line 7-7′ is depicted inFIG. 2B. As shown, the mandrel 20 is planar having two faces or sides(e.g., a front face/side and a back face/side). As described herein, themandrel 20 may include a positive mandrel portion 22 and a negativemandrel portion 24. The positive mandrel portion 22 may be spaced apartfrom the negative mandrel portion 24 (e.g., such that the positivemandrel portion 22 and the negative mandrel portion 24 are notelectrically coupled and/or not in contact with each other). As shown, apassage “p” separates the two portions 22, 24 (within which aninsulative separator may be located). In addition, the mandrel 20 asshown may include a removable portion 26. Between the removable portion26 and the positive and negative mandrel portions 22, 24 is thedecoupling region 28 (e.g., depression 29 as shown) configured to assistthe removal of the removable portion 26 from the positive and negativemandrel portions 22, 24.

Further, the mandrel 20 further defines a positive connector elementchannel 23 and a negative connector element channel 25 for receivingpositive and negative connector elements, respectively. For example, theconnector element channels 23, 25 may be dimensioned and configured toaccept connector elements 42, 44 (such as feedthrough pins shown in FIG.1). Further, as shown, the positive connector element channel 23 islocated, or placed, closer to the axis 8, or midline, of the mandrel 20than the negative connector element channel 25, which is illustrated bythe distance “d2” from the positive connector element channel 23 to theaxis 8 compared to the distance “d1” from the negative connector elementchannel 25 to the axis 8. In at least one embodiment, the channels 23,25 may be equidistant from the axis 8. Further, in at least oneembodiment, the negative connector channel 25 may be closer to the axis8 than the positive connector channel 23. It is to be understood thatthe channels can be placed at any location on the mandrel 20. Further,it is also to be understood that having the connector elementspositioned at two different distances from the axis 8, a battery topcover 72 (shown in FIGS. 1 and 5A-5B) can be constructed to fit over themandrel 20 and electrodes 30, 32 located, or placed, (e.g., wrapped,etc.) around, or about, the mandrel 20 in only one position, which mayinsure that the terminals can be more quickly identifiable as positiveand negative.

Further, as shown in FIG. 2A, the removable portion 26 can be separated,or removed, from positive mandrel portion 22 and negative mandrelportion 24 along the depression 29. As described herein, the depression29 can be deep enough such that the mandrel 20 can be broken along thedepression 29 resulting in individual positive and negative mandrelportions 22, 24 of the mandrel 20. For example, after the positive andnegative mandrel portions 22, 24 have been separated from the removableportion 26, the negative mandrel portion 24 are spaced apart from thepositive mandrel portion 22, e.g., such that the negative mandrelportion 24 is not electrically coupled to the positive mandrel portion22. More specifically, the positive mandrel portion 22 and the negativemandrel portion 24 may be separated by the passage “p” located betweenthe positive mandrel portion 22 and the negative mandrel portion 24. Inat least one embodiment, an insulative separator portion may be locatedin the passage “p” to, e.g., provide structural support to the mandrel20. As shown, the mandrel 20 may further define an orientation notch 31shown as a foot-type aperture on the axis 8 of the mandrel 20. In theembodiment depicted in FIG. 2A, the “foot” of the notch 31 points towardnegative mandrel portion 24 of the mandrel 20.

Electrodes 30, 32 may be attached to the mandrel 20 as shown in FIG. 3.More specifically, a positive electrode 30 may be attached to thepositive mandrel portion 22 and a negative electrode 32 may be attachedto the negative mandrel portion 24. As shown, the electrodes 30, 32 areattached to opposite sides of the mandrel 20.

The positive electrode 30 can be coated with a positive active material38. As illustrated, the positive electrode 30 has a proximal end 34 thatmay not be coated with active material, e.g., for coupling to thepositive mandrel portion 22. The proximal end 34 may be attached topositive mandrel portion 22 of the mandrel 20 at a selected, orspecific, coupling region 37. Similarly, the negative electrode 32 canbe coated with a negative active material 39, and the proximal end (notshown) of the negative electrode 32 may not be coated with activematerial. The proximal end of the negative electrode 32 may be attachedto the negative mandrel portion 24 of the mandrel 20 at a selected, orspecific, coupling region (not shown) similar to the coupling region 37of the positive mandrel portion 22.

The electrodes 30, 32 can be attached to the positive mandrel portion 22and negative mandrel portion 24, respectively, by welding (e.g., laserwelding, ultrasonic welding, resistance welding, etc.), adhering, one ormore mechanical processes (e.g., crimping, swaging, etc.), friction stirwelding, diffusion, etc. As shown, multiple laser welds 81 may be usedto electrically couple the proximal end 34 of the positive electrode 30to the coupling region 37 of the positive mandrel portion 22. In atleast one embodiment, a combination of two or more different types ofwelds may be used to electrically couple the electrodes 30, 32 and themandrel portions 22, 24, respectively.

It is to be understood that the positive active material 38 may includeany one or more positive active materials used in electrode technology.For example, the positive active material 38 may include lithium cobaltoxide (e.g., for use in rechargeable batteries), carbon monofluoride(CF_(x)), silver vanadium oxide, lithium iron phosphate, lithiumpolonium, one or more oxides, one or more phosphates, one or moresilicates, one or more fluorophosphates, etc. and/or combinations oralloys thereof. Similarly, the negative active material 39 may includeany one or more negative active material used in electrode technology.For example, the negative active material 39 may include lithiumtitanate, artificial graphite powder (MCMB), lithium, one or moreoxides, one or more metals or bimetals, silicon, etc. and/orcombinations or alloys thereof.

Both the positive and negative electrodes 30, 32 can be coated on oneside or both sides to provide an electron flow suitable to generate acurrent. It is to be understood that coating the electrodes on bothsides with active material may allow for more efficient use of the twosides of the electrodes, which may result in increased energy and powerin contrast to a single side coated electrode. Further, it is to beunderstood that the proximal and/or distal ends of the electrodes 30,32, may not be coated on one or both sides. Still further, it is to beunderstood that any suitable combination of coatings and coated portionsof the electrode(s) is within the scope of this disclosure.

As shown in FIGS. 1 and 4, positive and negative connector elements 42,44 such as, e.g., the feedthrough pins, may be placed, or located, inthe connector element channels 23, 25 and coupled therein. The connectorelements 42, 44 may be electrically coupled (e.g., conductivelyconnected, etc.) and mechanically coupled to the portions 22, 24,respectively, of the mandrel 20 using one or more processes such as,e.g., welding (e.g., laser welding, ultrasonic welding, resistancewelding, etc.), crimping, stamping, adhering, swaging, friction stirwelding, diffusion, etc. In at least one embodiment, connector elementsmay be spot welded (e.g., using laser welding) in one or more locations(e.g., a plurality of locations along the length of the connectorelements). In at least one embodiment, the channels 23, 25 (e.g.,coupling regions) may be “C”-shaped or “U”-shaped” and the channels 23,25, may be crimped such that the “C”-shape or “U”-shape is deflectedinwardly compressing the connector element located within the “C”-shapedor “U”-shaped channel. In at least one embodiment, an adhesive orflowable/moldable material (e.g., conductive polymer) may be used at oneor more locations (e.g., a single location, a plurality of locations,etc.) to couple the connector elements 42, 44 in the connector elementchannel 23, 25.

Additional elements of the electrode assembly 16 depicted in FIG. 1include an insulator 70 and a battery top cover 72. The insulator 70 mayinsulate the electrodes 30, 32 and the positive and negative mandrelportions 22, 24 from the battery top cover 72. Further, connectorelements 42, 44 may extend through the insulator 70 and the battery topcover 72 and can be used as battery terminals 80, 82. The electrodeassembly 16 may further include ferrules 84 attached (e.g., adhered,welded, etc.) to the battery top cover 72 to stabilize the terminals andisolate them from the battery top cover 72. A glass seal or sleeve (notshown) may be placed over each connector element 42, 44 prior to theplacement of ferrules 84 to provide a seal between the connectorelements and the battery top cover 72 and further insulate the ferrules84 from the connector elements 42, 44.

The ferrules 84 may include (e.g., be formed of, etc.) titanium,titanium alloys, stainless steel, etc., and/or combinations or alloysthereof. The insulator 70 may include (e.g., be formed of, etc.) anyinsulating material such as, e.g., polyethylene, polypropylene,polyethylene terephthalate, polyimide, ethylene/tetrafluoroethylenecopolymer (ETFE), etc., and/or combinations thereof. In at least oneembodiment, the insulator may be a non-conductive film such as, e.g.,DUPONT KAPTON polyimide film.

Although the electrode assembly 16 depicted in FIGS. 1-5 utilizes apositive and negative terminal without utilizing the case (e.g., thecase is neutral), in other embodiments, a connection element (e.g., studpin) can be coupled (e.g., welded) to the battery cover and may beconfigured for electrical coupling with one of the connector elements42, 44 such that the case may be electrically coupled to one of theconnector elements 42, 44 to provide the case as either a negativepotential terminal/connection point or a positive potentialterminal/connection point.

An end view an exemplary coiled electrode assembly 16 is shown in FIG.4. As shown, the electrodes 30, 32 have been located (e.g., wrapped,wound, etc.) around the mandrel 20 (e.g., around axis 8) to create thecoiled electrode assembly 16. As described herein, the mandrel 20 mayinclude channels 23, 25 for the connector elements 42, 44 defined on thesame side (or face) of the mandrel 20. Further, the electrodes 30, 32may be electrically coupled to their respective mandrel portions 22, 24on opposite sides of the mandrel 20. For example, uncoated portions(e.g., proximal end 34) of the electrodes 30, 32 can be connected to thepositive and negative mandrel portions 22, 24 of the mandrel 20.

The separators, which are represented by white space between theelectrodes 30, 32 in FIG. 4, can be located, or placed, so as to haveopposing side adjacent to the positive electrode 30 and the negativeelectrode 32, respectively. When wound, the separators may isolate(e.g., electrically isolate or insulate, physically separate, etc.) thepositive and negative electrodes 30, 32 from each other. The separatorscan be attached to the mandrel 20 using any one or more processes orremain unattached, or uncoupled, to the mandrel 20. In at least oneembodiment, the separators can be connected using adhesive material etc.that is configured to couple, or adhere, the separators to the mandrel20. Exemplary tape adhesive material may include polypropylene,polyethylene, polyester, nylon resin, etc. Exemplary adhesives mayinclude, e.g., polyvinylidenefluoride (PVDF), co-polymers ofpolyhexafluoropropylene-polyvinylidenefluoride, poly(vinylacetate),polyvinylalcohol, polyethylene oxide, polyvinylpyrolidone, alkylatedpolyethylene oxide, polyvinyl ether, poly(methylmethacrylate),poly(ethylacrylate), polytetrafluoroethylene, polyvinylchloride,polyacrylonitrile, polyvinylpyridine, styrene-butadiene rubber, silicon,etc. and mixtures thereof.

Generally, to wind the electrodes 30, 32 around the mandrel 20, themandrel 20 may be rotated using the removable portion 26 about axis 8.In other words, the removable portion 26 may be coupled to a rotationapparatus and the rotation apparatus may rotate the mandrel 20 such thatthe electrodes 30, 32 and one or more separators may be located around,or about, the mandrel 20. In at least one embodiment, the removableportion 26 may include a clamp portion. The clamp portion may be coupledto the rotation apparatus and may be configured to assist in therotation of the mandrel 20 to wind the electrode 30, 32 thereabout.Further, the removable portion 26 may include any one or more featuresor portions that may further assist or aid in assembly (e.g., incoupling the mandrel to the rotation apparatus).

The rotation process may be performed manually or automatically. In atleast one embodiment, the removable portion 26 of the mandrel 20 may beattached to a ligature or other holding mechanism (not shown) that canbe turned by a motor. Once wound, any adhesive or attachment apparatusor material may be used to keep the electrodes in place (e.g., such thatthe electrodes 30, 32 do not unwind or unroll). For example, insulatingtape can be used such as, e.g., Teflon, or polyimide tape such as, e.g.,DUPONT KAPTON. In at least one embodiment, polymer material may bemolded over one or both end regions or portions of the mandrel 20, e.g.,to provide insulation between the electrodes 30, 32 and any otherportion of the electrode assembly 16 or battery, to provide structure tothe electrode assembly 16, to be used as the removable portion 26 of themandrel 20, etc.

FIGS. 5A-5B show a battery assembly 10 including the coiled electrodeassembly 16 made using a mandrel 20 described herein with reference toFIGS. 1-4. More specifically, the battery assembly 10 is depicted inFIG. 5A within an exemplary battery case 64 located over the positiveand negative mandrel portions (not shown) and coiled electrodes (notshown) before the removable portion 26 is removed. Further, the batteryassembly 10 is shown in FIG. 6B with the removable portion 26 removed.As illustrated, the battery case 64 is dimensioned so as to approximatethe size of the mandrel without removable portion 26. Further,separation of the removable portion 26 may result in individual positiveand negative mandrel portions 22, 24 of the mandrel 20 integrated intothe coiled electrode assembly 16. In at least one embodiment, the coiledelectrode assembly 16 can be wound or coiled to a tension desired toaccommodate the battery rather than coiling the coiled electrodeassembly to a tension that allows the mandrel 20 to be removed from theelectrode coil.

The various exemplary mandrels and/or electrode assemblies describedherein may include features and/or elements described in U.S. PatentApplication Publication No. 2011/0250481 A1 entitled “COIL SEAL TOSECURE THE ELECTRODE WINDINGS OF AN ELECTROCHEMICAL CELL” filed onMar.9, 2011, U.S. patent application Ser. No. 13/332,686 entitled“THROUGH WELD INTERCONNECT JOINT” filed on Dec. 21, 2011, and U.S.Patent Application Publication No. 2012/0084979 A1 entitled “COILINGDEVICE FOR MAKING AN ELECTRODE ASSEMBLY AND METHODS OF USE” filed onSep. 12, 2011, issued as U.S. Pat. No. 8,832,914 issued Sep. 16, 2014,each of which are also incorporated herein by reference in theirentireties. Further, U.S. patent. application. Ser. No. 13/456,714entitled “MANDREL FOR ELECTRODE ASSEMBLIES” filed on Apr. 26, 2012, nowU.S. Pat. No. 8,778,521 issued Jul. 15, 2014 is also incorporated hereinby reference in its entirety.

Exemplary mandrels may define one or more coupling regions that mayinclude one or more materials and/or structures configured to provideeffective mechanical and electrical coupling to additional electrodeassembly elements such as connector elements (e.g., feedthrough pins),electrodes 30, 32 (e.g., foil electrodes), etc. For example, a couplingregion may include at least some of the same material as the element(e.g., connector element, electrode, etc.) to be coupled thereto. Forinstance, a positive electrode may be formed of aluminum, and thus, anelectrode coupling region of a positive mandrel portion includingaluminum may be provided for coupling the positive electrode thereto.Further, for example, one or more coupling features may be provided insuch coupling regions on the mandrel such as protrusions, bumps,apertures, channels, grooves, tabs, etc. that may further assist incoupling an element to the mandrel. Generally, the coupling region maydefine any one or more features (e.g., features formed by a process) tofurther assist in coupling an element to the mandrel.

The elements that may be couplable to the exemplary mandrels describedherein may also include different materials. For example, connectorelements such as feedthrough pins may include titanium and theelectrodes may include aluminum. As such, the exemplary mandrels mayprovide more than one region that includes different material for eachdifferent element to be coupled thereto (e.g., coupled by welding,crimping, stamping, pressing, etc.). For example, a mandrel portion,such as a positive or negative mandrel portion 22, 24, may include tworegions: an electrode coupling region configured for coupling themandrel portion to an electrode and a connector element coupling regionconfigured for coupling the mandrel portion to a connector element. Theelectrode coupling region may include one or more conductive materialsand/or one or more features configured for electrical and mechanicalcoupling to an electrode, such as electrodes 30, 32 (e.g., foilelectrodes). The connector element coupling region may include one ormore conductive materials and/or one or more features configured forelectrical and mechanical coupling to a connector element 42, 44 (e.g.,feedthrough pins). The material included in the connector elementcoupling region may be different than the material included in theelectrode coupling region, e.g., to accommodate connector elements thatinclude different material than the electrodes. Exemplary mandrels, suchas may be used in the configurations shown in FIGS. 1-5 or any otherelectrode assembly, including one or more electrode coupling regions andconnector element coupling regions are depicted in FIGS. 6-13 and 15-20.

The exemplary mandrels and electrode assemblies may be used in batteriesfor medical devices (e.g., implantable medical devices) such as, e.g.,defibrillators, pacemakers, neural stimulators, cardiacresynchronization therapy devices, drug pumps, insulin pumps, etc.and/or for any other device that may utilize electricity. In otherwords, exemplary medical devices (e.g., implantable medical devices) mayinclude the mandrels and/or electrode assemblies described herein (e.g.,in a battery) as well as any other components and/or features used toprovide therapy by the medical devices. Such batteries may provide power(e.g., electricity) to the medical devices. For example, the batteriesmay be electrically coupled to components and/or features of the medicaldevices to provide power to such components and/or features.

The exemplary mandrel 120 depicted in FIGS. 6A-6D includes a positivemandrel portion 122, a negative mandrel portion 124, and a removableportion 126 arranged along axis 108. For simplicity, only the positivemandrel portion 122 will be further described in detail. It is to beunderstood that the negative mandrel portion 124 may also include thesame or similar elements and/or features as the positive mandrel portion122 and may further be configured in the same or similar ways as thepositive mandrel portion 122. Further, although in this embodiment, thepositive and negative mandrel portions 122, 124 are substantially thesame size (e.g., width, height, thickness, etc.), in other embodiments,positive and negative mandrel portions of an exemplary mandrel may bedifferent sizes e.g., for manufacturability, etc.

The positive mandrel portion 122 may be described as extending along theaxis 108 from a first end 116 to a second end 118. The positive mandrelportion 122 may define a front side 112 (the surface shown in FIGS.6A-C) and a rear side 114 (the surface hidden from view in FIGS. 6A-C).Side surfaces 115, or sides, may extend between the front side 112 andthe rear side 114. The front and rear side 112, 114 (e.g., front andrear surfaces) may lie generally in planes parallel to the axis 108.Further, as depicted, one side surface 115 may define a curvature whilean interior side surface 117 may be generally planar (e.g., parallel tothe axis 108). The curved side surface 115 may be curved to, e.g.,provide a smooth curve for coupling an electrode about. In otherembodiments, the side surface 115 may be generally planar and/or theinterior side surface 117 may be curved. Generally, the positive mandrelportion 122 may described as extending longitudinally along the axis 108such that the mandrel portion 122 has a greater length (e.g., the lengthbeing defined by a direction parallel to the axis 108) than width (e.g.,the width being defined by a direction perpendicular to the axis 108,the width extending along the front and rear sides 112, 114, etc.).Further, the width of the positive mandrel portion 122 may be greaterthan the thickness (e.g., the thickness being defined by the sidesurfaces 115, 117). One or more of the mandrels and/or mandrel portionsdescribed here may share the same, or similar, geometric properties.

As depicted, the positive mandrel portion 122 includes a primary portion150 including a first conductive material and an electrode couplingportion 160 including a second conductive material. As used herein, theterm “primary portion” may refer to a portion of a mandrel portion thatis generally larger than the other portions of the mandrel portion. Forexample, a “primary portion” may define the majority of the mandrelportion. Each of the first conductive material and the second conductivematerial may be steel, platinum, aluminum, titanium, nickel, copper,niobium, etc. and/or combinations or alloys thereof such as, e.g.,titanium alloy such as grade 5 or grade 23, platinum-iridium such as 90percent platinum/10 percent iridium, aluminum sleeve or shell over atitanium core, stainless steel, coated/plated metal, etc. The primaryportion 150 and the electrode coupling portion 160 may be electricallyand mechanically coupled to each other through various processes. Forexample, the primary portion 150 may be mechanically coupled to theelectrode coupling portion 160 through one or more processes such as,e.g., welding, stamping, pressing, electromagnetic forming, hotisostatic processing, thermal mechanical or thermomechanical forming,hydro mechanical forming, diffusion bonding, etc.

As shown in the exploded view of FIG. 6B, the primary portion 150defines a mating region 152 configured to mate with a mating region 162defined by at least a portion of the electrode coupling portion 160 tomechanically couple the primary portion 150 and the electrode couplingportion 160. For example, the mating region 152 of the primary portion150 and the mating region 162 of the electrode coupling portion 160 maybe moved towards and adjacent to one another to mechanically couple theprimary portion 150 and the electrode coupling portion 160. Further, themechanical coupling of the primary portion 150 and the electrodecoupling portion 160 may also electrically couple the primary portion150 and the electrode coupling portion 160.

More specifically, the mating region 152 of the primary portion 150 maydefine an opening 154 configured to receive at least a portion of themating region 162 of the electrode coupling portion 160. Although theopening 154 as depicted includes flat or planar surfaces, the opening154 may further define one or more features to facilitate, or assist,the coupling of the electrode coupling portion 160 therein. For example,although not depicted, the surfaces inside the opening 154 may include,or contain, one or more protrusions, bumps, recesses, ridges, apertures,grooves, channels, incisions, formed regions, etc. configured to matewith the mating region 162 of the electrode coupling portion 160.

The electrode coupling portion 160 may be nested within the opening 154so as to expose a surface 164 of the electrode coupling portion 160 forcoupling of an electrode thereto (e.g., coupled by welding, crimping,stamping, pressing, etc.). The surface 164 may be substantially flat orplanar to provide an effective surface for the coupling of an electrode(e.g., foil electrode). In at least one embodiment, the surface 164 mayfurther define one or more features to facilitate, or assist, thecoupling of an electrode thereto. For example, although not depicted,the surface 164 may contain one or more protrusions, bumps, recesses,ridges, apertures, grooves, channels, incisions, roughness, formedregions, etc. configured to mate with an electrode.

In at least one embodiment, the opening 154 may be substantially thesame size as the electrode coupling portion 160. In other words, thedepth of the opening 154 may be the same as, or similar to, thethickness of the electrode coupling portion 160, the length of theopening 154 may be the same as, or similar to, the length of theelectrode coupling portion 160, and the width of the opening 154 may bethe same as, or similar to, the width of the electrode coupling portion160.

In at least one embodiment, the opening 154 may not be the same size asthe electrode coupling portion 160. For example, the thickness of theelectrode coupling portion 160 may be greater than the depth of theopening 154 such that the exposed surface 164 of the electrode couplingportion 160 may extend outward from surface 158 of the primary portion150 (e.g., the electrode coupling portion 160 may define a bulge abovethe surface 158). Further, for example, the thickness of the electrodecoupling portion 160 may be less than the depth of the opening 154 suchthat the exposed surface 164 of the electrode coupling portion 160 islocated below the surface 158 of the primary portion 150 (e.g., theelectrode coupling portion 160 may define recess below the surface 158).Still further, the perimeter of the electrode coupling portion 160 maybe slightly larger than the perimeter of the opening 154 of the primaryportion 150 so as to provide a tight interference fit when mechanicallycoupled (e.g., when the electrode coupling portion 160 is located in theopening 154)

As shown in FIG. 6B, the sides surfaces 155 of the opening 154 may besubstantially flat. As shown in the illustrative cross sectional viewtaken across line 110-110′ depicted in FIG. 6D, alternatively, the sidessurfaces 161 of the electrode coupling portion 160 may not besubstantially flat. For example, as shown, the side surfaces 161 of theelectrode coupling portion 160 may be pointed, or beveled, which, e.g.,may assist in coupling of the electrode coupling portion 160 and theprimary portion 150 to each other.

The primary portion 150 may define a connector element coupling region170. Generally, the connector element coupling region 170 (indicated byarrows in FIGS. 6A & 6D and by a dotted outline in FIG. 6C) may define aregion where a connector element may be coupled (e.g., coupled bywelding, crimping, stamping, pressing, etc.). For example, the connectorelement coupling region 170 may include a connector element channel 174defined by the primary portion 150 configured for receiving a connectorelement to be coupled therein (e.g., coupled by welding, crimping,stamping, pressing, etc.). As shown in FIG. 6D, the channel 170 in thisembodiment defines a “U”-shape. The channel 174, however, may be anyshape that facilitates the coupling of a connector element (e.g.,“C”-shaped to snap fit a connector element therein, “V”-shaped toreceive a connector element by insertion at one end or the other, etc.).

When the primary portion 150 and the electrode coupling portion 160 arecoupled together (e.g., mechanically and electrically coupled), thepositive mandrel portion 122 may define an electrode coupling region 172(indicated by arrows in FIGS. 6A & 6D and by a dotted outline in FIG.6C). The electrode coupling region 172 may define a region where anelectrode may be coupled. For example, the flat surface 164 of theelectrode coupling portion 160 may provide the electrode coupling region172 for coupling an electrode thereto. In at least one embodiment, acoating (e.g., polyvinylidene fluoride (PVDF) electrode slurry binder)may be applied to the electrode coupling region 172, e.g., to eliminateor slow penetration of electrolyte to a weld zone, create a protectivebarrier, etc.

In essence, the connector element coupling region 170 may be defined bythe primary portion 150 and the electrode coupling region 172 may bedefined by the electrode coupling portion 160. Thus, the materials andfeatures of the primary portion 150 may be configured to provideeffective coupling to a connector element and the materials and featuresof the electrode coupling portion 160 may be configured to provideeffective coupling to an electrode.

For example, the primary portion 150 may include a first materialconfigured to be coupled to a connector element and the electrodecoupling portion 160 may include a second material configured to becoupled to an electrode. The first and second materials may be differentor the same. In at least one embodiment, the primary portion 150 mayinclude titanium, e.g., to provide effective electrical and mechanicalcoupling to titanium connector elements (such as feedthrough pins,etc.), and the electrode coupling portion 160 may include aluminum,e.g., to provide effective electrical and mechanical coupling toaluminum electrodes.

Further, and generally, the negative mandrel portion 124 may alsoinclude a primary portion including a first conductive material and anelectrode coupling portion including a second conductive materialsimilar to the primary portion 150 and the electrode coupling portion160 of the positive mandrel portion 122. The first conductive materialof the primary portion of the negative mandrel portion 124 may bedifferent than or the same as the second conductive material of theelectrode coupling portion of the negative mandrel portion 124. Further,the first conductive material of the primary portion of the negativemandrel portion 124 may be different than or the same as the firstconductive material of the primary portion 150 of the negative mandrelportion 122, and the second conductive material of the electrodecoupling portion of the negative mandrel portion 124 may be differentthan or the same as the second conductive material of the electrodecoupling portion 160 of the positive mandrel portion 122. For example,the electrode to be coupled to the positive mandrel portion 122 mayinclude different material than the electrode to be coupled to thenegative mandrel portion 124, and thus, the electrode coupling portionsof the positive and negative mandrel portions 122, 124 may includedifferent material to correspond to the electrode to be coupled thereto(e.g., to provide effective coupling). Further, for example, theconnector element to be coupled to the positive mandrel portion 122 mayinclude different material than the connector element to be coupled tothe negative mandrel portion 124, and thus, the primary portions of thepositive and negative mandrel portions 122, 124 may include differentmaterial to correspond to the connector element to be coupled thereto(e.g., to provide effective coupling).

Another exemplary mandrel 220 is depicted in FIGS. 7A-7D. The mandrel220 includes a positive mandrel portion 222, a negative mandrel portion224, and a removable portion 226 arranged about axis 208. Similar to thepositive mandrel portion 122 of the mandrel 120 of FIGS. 6A-6D, thepositive mandrel portion 222 of the mandrel 220 includes a primaryportion 250 and an electrode coupling portion 260 mechanically andelectrically coupled to each other. Further, the primary portion 250defines a connector element coupling region 270 (e.g., including a“U”-shaped channel) for receiving and for coupling a connector elementthereto (e.g., coupled by laser welding, ultrasonic welding, crimping,stamping, pressing, etc.), and the electrode coupling portion 260defines an electrode coupling region 272 (e.g., a flat surface) forcoupling an electrode thereto (e.g., coupled by laser welding,ultrasonic welding, crimping, stamping, pressing, etc.).

Differing from the mandrel 120, however, the electrode coupling portion260 of the positive mandrel portion 222 is located in a corner region ofthe primary portion 250 such that two side surfaces 261 of the electrodecoupling portion 260 define a portion of the side surface 223 of thepositive mandrel portion 222. Similar to the mandrel 120 of FIGS. 6A-6D,the primary portion 250 and the electrode coupling portion 260 mayinclude different conductive materials configured to provide effectivecoupling to elements including different conductive materials.

Further, the negative mandrel portion 224 of the mandrel 220 includes aprimary portion 280 and an electrode coupling portion 282. As shown, theelectrode coupling portion 282 of the negative mandrel portion 224 islocated on the opposite face, or side, of the mandrel 220 as theelectrode coupling portion 260 of the positive mandrel portion 222.

As shown in the exploded view of FIG. 7B, the primary portion 250 maydefine a mating region 252 for coupling to a mating region 262 of theelectrode coupling portion 260. The mating region 252 may define anopening 254 that includes a flat surface 256 and two side surfaces 258for receiving the mating region 262 of the electrode coupling portion260. As shown in the cross sectional view taken across line 210-210′depicted in FIG. 7D, the side surfaces 258 of the opening 254 and thesides surfaces 261 of the electrode coupling portion 260 may besubstantially flat. The coupling portion 260 may be coupled in theopening 254 using, e.g., laser welding, resistance welding, diffusionbonding, crimping, pressing (using surface features), etc.

Different than the embodiments depicted in FIGS. 6A-6D and 7A-7D, anelectrode coupling portion may also be mechanically and electricallycoupled to a primary portion through one or more deposition techniquessuch as chemical vapor deposition, plasma vapor deposition, ionbombardment, sputtering, ion beam deposition, atmospheric pressure iondeposition, etc. For example, an exemplary mandrel 320 including apositive mandrel portion 322 and a negative mandrel portion 324, eachincluding an electrode coupling portion 360, 380, respectively, that hasbeen deposited is depicted in FIGS. 8A-8B.

Although each of the positive and negative mandrel portions 322, 324include deposited electrode coupling portions 360, 380, only thepositive mandrel portion 322 will be described further herein in detailfor simplicity. It is to be understood that the negative mandrel portion324 may include the same or similar features and/or elements of thepositive mandrel portion 322 and may be configured in the same, or in asimilar, way.

As shown, the positive mandrel portion 322 may include a primary portion350 and an electrode coupling portion 360. The primary portion 350defines a region upon which the electrode coupling portion 360 may bedeposited. In at least one embodiment, the region may define a flat orplanar surface upon which the deposited electrode coupling portion 360may be deposited. In at least one embodiment, the region may define arecess, or pocket, for receiving the deposited electrode couplingportion 360. In at least one embodiment, the region may define arecessed, roughened, smooth (e.g., polished), etc. surface for receivingthe deposited electrode coupling portion 360.

The electrode coupling portion 360 may be deposited on the region of theprimary portion 350 using one or more various techniques or processes.For example, the electrode coupling portion 360 may be deposited usingchemical vapor deposition. For example, one or more masking processes(e.g., taping, coating such as wax coating or sacrificial/removablemask, painting, etc.), etching processes, etc. may be used to define theelectrode coupling portion 360.

A cross sectional view of the mandrel 320 taken across line 310-310′ isdepicted in FIG. 8B. As shown, the electrode coupling portion 360 mayinclude one or more layers formed on the primary portion 350 having athickness 374, or depth, that is greater than or equal to about 1micron, about 5 microns, about 10 microns, about 25 microns, about 50microns, etc. Further, the electrode coupling portion 360 may form alayer on the primary portion 350 having a thickness 374, or depth, thatis less than or equal to about 60 microns, about 70 microns, about 85microns, about 100 microns, about 150 microns, about 200 microns, etc.The primary portion 350 may define a bond surface configured forreceiving the one or more layers of the electrode coupling portion 360.In at least one embodiment, the electrode coupling portion 360 mayextend along, or define, a length that is substantially the same as thewidth of an electrode (e.g., formed of foil) to be coupled thereto.Further, in at least one embodiment, the electrode coupling portion 360may extend along, or define, a width that covers the entire, or lessthan the entire, width of the primary portion 350.

After deposition, the electrode coupling portion 360 may define anelectrode coupling region 372 configured for the electrical coupling ofan electrode thereto (e.g., coupled by laser welding, ultrasonicwelding, crimping, stamping, pressing, etc.). Further, the primaryportion 350 may define a connector element coupling region 370configured for the electrical coupling of a connector element thereto(e.g., coupled by laser welding, ultrasonic welding, crimping, stamping,pressing, etc.). As shown, the connector element coupling region 370includes a channel 371 for receiving a connector element such as afeedthrough pin. The connector element coupling region 370 and theelectrode coupling region 372 may function in a similar manner to theconnector element coupling region 170 and the electrode coupling region172 described herein with reference to FIGS. 6A-6D.

Although the mandrels described herein with reference to FIGS. 6-8include primary portions coupled to electrode coupling portions (towhich electrodes may be coupled) using various processes, techniques,and structures, mandrels according to the present disclosure may includeprimary portions coupled to connector element coupling portions (towhich connector elements may be coupled) using the same or differentprocesses, techniques, and structures. In other words, the primaryportion may be configured to be electrically and mechanically coupled toan electrode (as opposed to a connector element as in the embodimentsdescribed with reference to FIGS. 6-8) and a connector element couplingportion (as opposed to an electrode coupling portion as in theembodiments described with reference to FIGS. 6-8) coupled to theprimary portion may be configured to be electrically and mechanicallycoupled to a connector element.

For example, an exemplary mandrel 420 that utilizes a connector elementcoupling portion is depicted in FIGS. 9A-9C. The mandrel 420 includes apositive mandrel portion 422, a negative mandrel portion 424, and aremovable portion 426. For simplicity, only the positive mandrel portion422 will be further described in detail. It is to be understood that thenegative mandrel portion 424 may also include the same or similarelements and/or features as the positive mandrel portion 422 and mayfurther be configured in the same or similar ways as the positivemandrel portion 422.

As depicted, the positive mandrel portion 422 includes a primary portion450 including a first conductive material and a connector elementcoupling portion 460 including a second conductive material differentthan the first conductive material. The primary portion 450 and theconnector element coupling portion 460 may be electrically andmechanically coupled to each other through various processes similar tothe exemplary processes used to couple the primary portion 150 and theelectrode coupling portion 160 described herein with reference to FIGS.6A-6D, or any other one or more coupling processes. For example, theconnector element coupling portion 460 may be inserted, press fit, orotherwise mated with the primary portion 450, etc. Further, any othercoupling processes described herein may be used to couple the primaryportion 450 to the connector element coupling portion 460.

As shown in the exploded view depicted in FIG. 9B, the primary portion450 may define a mating region 452 configured to mate with a matingregion 462 defined by at least a portion of the connector elementcoupling portion 460. In other words, the mating regions 452, 462 may beused to mechanically couple the primary portion 450 and the connectorelement coupling portion 460. For example, the mating region 452 of theprimary portion 450 and the mating region 462 of the connector elementcoupling portion 460 may be moved towards each other and adjacent toeach other to mechanically couple the primary portion 450 and theconnector element coupling portion 460. Further, the mechanical couplingbetween the primary portion 450 and the connector element couplingportion 460 may further provide electrical coupling therebetween.

More specifically, as shown, the mating region 452 of the primaryportion 450 may define an opening 454 configured to receive at least aportion of the mating region 462 of the connector element couplingportion 460. Although the opening 454 as depicted includes flat orplanar surfaces, the opening 454 may define one or more features tofacilitate, or assist, the coupling of the connector element couplingportion 460 therein, which may be similar to the features describedherein for coupling the primary portion 150 and the electrode couplingportion 160 with reference to FIGS. 6A-6D.

As shown in the cross sectional view of the mandrel 420 taken acrossline 410-410′ depicted in FIG. 9C, the mating region 452 of the primaryportion 450 may further define a channel 471 for receiving a connectorelement. In at least one embodiment, the channel 471 may be depositedwith titanium (e.g., for coupling to a titanium connector element). Whenthe connector element coupling portion 460 is received within theopening 454 (e.g., nested within the opening 454), the positive mandrelportion 422 may define a connector element coupling region 470 inside(e.g., across from) the channel 471 for coupling a connector elementthereto (e.g., coupled by laser welding, ultrasonic welding, crimping,stamping, pressing, etc.). More specifically, at least a portion of theconnector element coupling portion 460 may be configured to contact aconnector element such as a feedthrough pin located in the channel 471.For example, the connector element coupling portion 460 may bepositioned within the opening 454 such that at least a portion of asurface 464 of the connector element coupling portion 460 may beconfigured to contact a feedthrough pin (or any other connecter element)located in the channel 471 to provide mechanical and electrical couplingtherebetween. Although the surface 464 of the connector element couplingportion 460 as depicted includes a flat or planar surface, the surface464 may define one or more features to facilitate, or assist, thecoupling of the connector element coupling portion 460 within theopening 454, which may be similar to the features described herein forcoupling the primary portion 150 and the electrode coupling portion 160with reference to FIGS. 6A-6D. In at least one embodiment, the surface464 may define a channel or depression for at least partially receivinga connector element.

For example, although not depicted, the surface 464 may contain one ormore protrusions, bumps, recesses, ridges, deflectable portions,fingers, formed regions, etc. configured to contact a connector elementlocated within the channel 471.

In at least one embodiment, the opening 454 may be substantially thesame size as the connector element coupling portion 460. In other words,the depth of the opening 454 may be the same as, or similar to, thethickness of the connector element coupling portion 460, the length ofthe opening 454 may be the same as, or similar to, the length of theconnector element coupling portion 460, and the width of the opening 454may be the same as, or similar to, the width of the connector elementcoupling portion 460.

As depicted, the connector element coupling portion 460 may be a part oflarger portion of material 480 that includes a connector elementcoupling portion 482 to be used with (e.g., to be coupled to) thenegative mandrel portion 424 and a removable section 484 configured forremoval with the removable portion 426. Further, a decoupling region 486may be defined across at least part of the material 480.

As shown in the cross sectional view of the mandrel 420 taken acrossline 410-410′ depicted in FIG. 9C, the primary portion 450 may define anelectrode coupling region 472 (e.g., a flat surface) configured forcoupling an electrode thereto. The primary portion 450, and therefore,the electrode coupling region 472 of the positive mandrel portion 422may include a first conductive material configured for coupling to anelectrode and the connector element coupling portion 460, and therefore,the connector element coupling region 470, may include a secondconductive material configured for coupling to a connector element. Thefirst and second conductive material may be the same or different, e.g.,depending on the materials of the connector elements and the electrodes.For example, the connector element may include titanium, and thus, theconnector element coupling portion 460 and the connector elementcoupling region 470 may also include titanium. The electrode may includealuminum, and thus, the primary portion 450 and the electrode couplingregion 472 may include aluminum.

As described herein, various manufacturing techniques and processes maybe used to form the exemplary mandrel portions described herein.Exemplary mandrels that may be produced using progressive stamping,rolling, forging, forming, swaging, machining, etching, stamping,cutting, welding, extruding, electromagnetic forming, hot isostaticprocessing, thermal mechanical or thermomechanical forming, hydromechanical forming, etc. are described herein with reference to FIGS.10-13 and 15-20. For example, at least a portion of a connector elementcoupling portion of a mandrel portion may be positioned adjacent (e.g.,wrapped, swaged, stamped together, etc.) to at least a portion of anelectrode coupling portion of the mandrel portion to mechanically couplethe connector element coupling portion and the electrode couplingportion. The mechanical coupling between the connector element couplingportion and the electrode coupling portion may provide an electricalcoupling therebetween.

The exemplary mandrel 520 depicted in FIGS. 10A-10B includes a positivemandrel portion 522 and a negative mandrel portion 524 arranged alongaxis 508. When the mandrel 520 is used in (e.g., to form) a batteryassembly (e.g., when the electrodes are located, or placed, thereabout,etc.), the positive mandrel portion 522 may be spaced apart from thenegative mandrel portion 524 as depicted in FIG. 10A and as furtherdescribed herein with reference to the exemplary mandrel shown in FIGS.1-5 using any suitable structure (e.g., polymer portions, removableportions, etc.). As shown, the positive mandrel portion 522 and thenegative mandrel portion 524 may be similar, and as such, only thepositive mandrel portion 522 will be further described in detail. It isto be understood that the negative mandrel portion 524 may also includethe same or similar elements and/or features as the positive mandrelportion 522 and may further be configured in the same or similar ways asthe positive mandrel portion 522.

The positive mandrel portion 522 may be configured to be electricallyand mechanically coupled to a positive electrode to be located aroundthe mandrel 520 to be used in a battery assembly. Further, the positivemandrel portion 522 may be configured to be electrically andmechanically coupled to a positive connector element configured toextend outside of a battery casing in a battery assembly. To providesuch couplings, the positive mandrel portion 522 may include a connectorelement coupling portion 550 and an electrode coupling portion 560 thatare electrically and mechanically coupled to each other. For example, aportion of the connector element coupling portion 550 and a portion ofthe electrode coupling portion 560 may be positioned adjacent to eachother to mechanically couple them to each other. The mechanical couplingbetween the connector element coupling portion 550 and the electrodecoupling portion 560 may further provide an electrical couplingtherebetween.

As shown, about 85% of the connector element coupling portion 550 ispositioned adjacent to about 85% of the electrode coupling portion 560.More specifically, as shown in the cross section of the mandrel 520taken across line 510-510′ depicted in FIG. 10B, an outer surface 551 ofthe connector element coupling portion 550 may be positioned adjacent toan inner surface 561 of the electrode coupling portion 560. Although, asdescribed previously, about 85% of each of the outer surface 551 of theconnector element coupling portion 550 and the inner surface 561 of theelectrode coupling portion 560 are adjacent to each other, more or lessof the outer and inner surfaces, or any other surfaces, of the connectorelement coupling portion 550 and the electrode coupling portion 560 maybe positioned adjacent to each other such that they are effectivelymechanically coupled to each other. For example, at least about 5%,about 10%, about 15%, about 20%, about 25%, about 35%, about 50%, about65%, about 75%, about 85%, etc. of one or more surfaces of the connectorelement coupling portion 550 and the electrode coupling portion 560 maybe positioned adjacent to each other as long as they may be effectivelymechanically coupled to each other.

The connector element coupling portion 550, similar to previousconnector element coupling portions described herein, may be configuredto be coupled to a connector element. For example, the connector elementcoupling portion 550 may define a connector element coupling region 570(e.g., a region for coupling a connector element thereto using welding,adhesion, press fit, interference fit, crimping, etc.). As shown, theconnector element coupling portion 550 defines a channel 571 forreceiving a connector element 590 as shown in FIG. 10B. In at least oneembodiment, the channel 571 may be formed by stamping the channel 571into the material of the connector element coupling portion 550 beforebeing coupled to the electrode coupling portion 560. Exemplary formationof the channel 571 is further described herein with reference to FIG.13B.

The electrode coupling portion 560 may be configured to be coupled to anelectrode. For example, the electrode coupling portion 560 may define anelectrode coupling region 572 (e.g., a region for coupling an electrodethereto by laser welding, ultrasonic welding, crimping, stamping,pressing, etc.). As shown, the electrode coupling portion 560 may definea planar, or flat, surface 564 to be coupled to an electrode. Althoughthe electrode coupling region 572 and the surface 564 are depicted asbeing a top side in FIGS. 10A-10B, it is to be contemplated that theelectrode coupling region 572 and the surface 564 may be located on theother, or bottom, side 573 (indicated in FIG. 10B) of the electrodecoupling portion 560.

As shown, the positive mandrel portion 522 is wider (e.g., a directionperpendicular to the axis 508) than the negative mandrel portion 524,e.g., for manufacturability, to provide electrode coupling regions onopposite sides of the mandrel, etc. In other embodiments, the positivemandrel portion 522 may be substantially the same size as the negativemandrel portion 524.

As described herein, at least a portion of a connector element couplingportion and at least a portion of an electrode coupling portion may bepositioned adjacent each other to mechanically couple the connectorelement coupling portion and the electrode coupling portion. Theportions of the connector element coupling portion and the electrodecoupling portions that are positioned adjacent to each other to providemechanical coupling may be wrapped, swaged, crimped, stamped, etc. abouteach other to provide the mechanical coupling. The mechanical couplingmay further provide an electrical coupling between the connector elementcoupling portion and the electrode coupling portion.

In at least one embodiment, at least a portion of an electrode couplingportion is wrapped about at least a portion of the connector elementcoupling portion to mechanically couple the connector element couplingportion and the electrode coupling portion. For example, as shown inFIGS. 10A-10B, the electrode coupling portion 560 wraps almostcompletely around the connector element coupling portion 550. Further,the connector element coupling portion 550 and the electrode couplingportion 560 may be crimped about each other simultaneously (e.g., bent,or molded, to each other at the same time).

The mandrel 520 may further include a removable portion that may beremovably coupled to each of the positive and negative mandrel portions522, 524. The removable portion may be part of one or both of theconnector element coupling portion 550 and the electrode couplingportion 560, or may be a separated removable portion coupled thereto.

Although not depicted, the positive mandrel portion 522 may furtherinclude a tying portion (e.g., a layer) located between (e.g.,sandwiched between) one or more portion (e.g., all) of each of theconnector element coupling portion 550 and the electrode couplingportion 560. The tying portion may provide effective coupling, corrosionresistance, and/or various mechanical properties to the mandrel portion522. The tying portion may be chosen, or selected, to have a melt pointbetween the melt point of the materials of each of the connector elementcoupling portion 550 and the electrode coupling portion 560. Forexample, the connector element coupling portion 550 may include titaniumand may have a melt point of about 1600 degrees Celsius, and theelectrode coupling portion 560 may include aluminum and may have a meltpoint of about 600 degrees Celsius. In this example, the material of thetying portion may be selected to have a melt point between about 600degrees Celsius and about 1600 degrees Celsius. In at least oneembodiment, the tying portion may include copper and may have a meltpoint of about 1100 degrees Celsius.

The exemplary mandrels described herein may be provided (e.g., produced,manufactured, etc.) by one or more various chemical and physicalprocesses. An exemplary method of providing mandrel portions isdescribed herein with reference to FIG. 11. Although a single mandrelportion is described in the exemplary method, it is to be understoodthat each mandrel portion may be produced concurrently and/orseparately.

The exemplary method 600 depicted in FIG. 11 includes providing aconnector element coupling portion 602 and providing an electrodecoupling portion 604. The connector element coupling portion may includea first conductive material and the electrode coupling portion mayinclude a second conductive material. In one or more embodiments, thesecond conductive material may be different than the first conductivematerial. For example, the first material may be titanium and the secondmaterial may be aluminum.

In at least one embodiment, the connector element coupling portion maybe a sheet of material. Further, in at least one embodiment, theconnector element coupling portion may be formed into a selected orspecific shape configured for coupling to the electrode coupling portionand/or for coupling to a connector element. For example, various shapesand/or features may be formed (e.g., by stamping, cutting, pressing,crimping, welding, etc.) in the connector element coupling portion suchas, e.g., channels, indentations, protrusions, roughened surfaces,fingers, openings, curves, etc. to facilitate coupling to the electrodecoupling portion and/or a connector element.

Likewise, in at least one embodiment, the electrode coupling portion maybe a sheet of material. Further, in at least one embodiment, theelectrode coupling portion may be formed into a shape configured forcoupling to the connector element coupling portion. For example, variousshapes and/or features may be formed in the electrode coupling portionsuch as, e.g., channels, indentations, protrusions, roughened surfaces,fingers, openings, curves, etc. to facilitate such couplings tofacilitate coupling to the connector element coupling portion and/or anelectrode.

The exemplary method 600 may further include coupling the connectorelement coupling portion and the electrode coupling portion 606.Generally, at least a portion of the connector element coupling portionmay be positioned adjacent to at least a portion of the electrodecoupling portion to couple the connector element coupling portion andthe electrode coupling portion. Coupling the connector element couplingportion and the electrode coupling portion 606 may include stamping,wrapping, crimping, welding, and/or swaging at least a portion of eachof the connector element coupling portion and the electrode couplingportion together. In other words, one or more portions of each of theconnector element coupling portion and the electrode coupling portionmay be wrapped, crimped, welded, stamped, and/or swaged to each other tosuch that they are mechanically coupled. Further, the mechanicalcoupling between the connector element coupling portion and theelectrode coupling portion may provide an electrical couplingtherebetween.

Further, as described herein, a tying portion (e.g., layer) may belocated between (e.g., sandwiched between) the connector elementcoupling portion and the electrode coupling portion before, or during,the coupling of the connector element coupling portion and the electrodecoupling portion 606. Still further, a removable portion may be providedas part of, or coupled to, one or both of the connector element couplingportion and the electrode coupling portion.

Perspective views of an exemplary mandrel portion being produced aredepicted in FIGS. 12A-12D. A first material 745 (e.g., sheet ofmaterial, ribbon of material, block of material, etc.) for the connectorelement coupling portion may be provided as shown in FIG. 12A. Asdescribed herein, the connector element coupling portion may includematerial that may be effectively coupled to a connector element, andthus, the first material 745 used to form the connector element couplingportion may include material that may be effectively coupled to aconnector element. For example, the first material 745 may include atleast some of the same material as the connector element to facilitateeffective coupling. In at least one embodiment, the sheet of materialmay include titanium to facilitate effective coupling to a titaniumconnector element.

A channel 747 may be formed in the first material 745 as shown in FIG.12B. The channel 747 may be configured to define a connector elementcoupling region and to receive a connector element for a batteryassembly. Although a channel is depicted in FIG. 12B, any one or morefeatures may be used to define a connector element coupling region. Thechannel 747 may be formed by stamping, bending, coining, rolling,machining, etc. the first material 745.

A second material 749 may be provided and positioned proximate (e.g.,below) the first material 745 as shown in FIG. 12C. The first material745 and the second material 749 may be sized relative to each other toprovide effective coupling. As shown, the second material 749 has alonger width 772 than the first material 745 and the second material 749and the first material 745 have about the same length 770. In otherembodiments, the second material 749 may have the same or shorter width772 than the first material 745 and/or the second material 749 may havea longer or shorter length 770 than the first material 745. Eachmaterial 745, 749 may have the same thickness such as, e.g., about 0.005inches, about 0.01 inches, about 0.02 inches, etc. In other embodiments,each material 745, 749 may have a different thickness. For example, thefirst material 745 may have a thickness of about 0.005 inches and thesecond material 749 may have a thickness of about 0.007 inches.

The first material 745 and the second material 749 may be mechanicallycoupled to each other by coupling at least a portion of the firstmaterial 745 to at least a portion of the second material 749 as shownin FIG. 12D. Generally, at least a portion of the first material 745 maybe positioned adjacent to at least a portion of the second material 749to couple the two materials. In at least one embodiment, at least aportion of the second material 749 may be wrapped about at least aportion of the first material 745, e.g., while being bent, to provideeffective mechanical coupling between the first material 745 and thesecond material 749. For example, the sides of the first material 745and the sides of the second material 749 may be moved towards each otherto be coupled to each other. As shown, the mechanical coupling betweenthe first material 745 and the second material 749 includes a first 180degree bend 761 and a second 180 degree bend 763. Each of the bends 761,763 may be formed concurrently (e.g., at the same time) or separately(e.g., one at a time).

Further, the bends 761, 763 for each of the first material 745 and thesecond material 749 may also be formed concurrently (e.g., at the sametime) or separately (e.g., one at a time). For example, the bends 761,763 for the first material 745 may be formed prior to locating the firstmaterial 745 proximate the second material 749. Then, the secondmaterial 749 may be bent or wrapped around the first material 745.

Further, for example, the bends 761, 763 for the second material 749 maybe formed prior to locating the first material 745 proximate the secondmaterial 749. In this example, after each of the first material 745 andthe second material 749 are formed or bent, the first material 745 maybe slid into the second material 749 to be adjacent to the firstmaterial 745 for mechanical coupling.

As shown in FIG. 12D, the first material 745 may provide a connectorelement coupling portion 751 and the second material 749 may provide anelectrode coupling portion 753. Taken together, the connector elementcoupling portion 751 and the electrode coupling portion 753 may form amandrel portion 755.

To further provide the coupling between the connector element couplingportion 751 and the electrode coupling portion 753, the portions 751,753 may be crimped, welded (e.g., laser welded, spot welded, etc.),adhered, etc. to each other. For example, a polymer portion may bemolded over at least a portion of the mandrel portion 755 tomechanically couple each of the connector element coupling portion 751and the electrode coupling portion 753 as described in U.S. patentapplication Ser. No. 13/456,700 entitled “ELECTRODE ASSEMBLIES INCLUDINGINSULATIVE PORTIONS” filed on Apr. 26, 2012, which is incorporatedherein by reference in its entirety.

Another exemplary mandrel 820 is depicted in FIGS. 13A-13E. Theexemplary mandrel 820 may include a positive mandrel portion 822 and anegative mandrel portion 824 arranged along an axis 808. Although eachof the positive and negative mandrel portions 822, 824 are depicted,only the positive mandrel portion 822 will be described in furtherdetail herein for simplicity. It is to be understood that the negativemandrel portion 824 may include the same or similar features and/orelements of the positive mandrel portion 822 and may be configured inthe same, or in a similar, way.

The positive mandrel portion 822 may include a connector elementcoupling portion 850 configured to be coupled to a connector element(e.g., coupled by laser welding, ultrasonic welding, crimping, stamping,pressing, etc.) such as, e.g., a feedthrough pin, and an electrodecoupling portion 860 configured to be coupled to an electrode (e.g.,coupled by laser welding, ultrasonic welding, crimping, stamping,pressing, etc.). Similar to the exemplary mandrel portion 520 describedhere with reference to FIGS. 10A-10B, the exemplary positive mandrelportion 822 may be produced using one or more various mechanicalprocesses such as progressive stamping, crimping, swaging etc. Forexample, at least a portion of the connector element coupling portion850 may be positioned adjacent to at least a portion of the electrodecoupling portion 860 to provide a mechanical coupling therebetween.Further, the mechanical coupling between the connector element couplingportion 850 and the electrode coupling portion 860 may provide anelectrical coupling therebetween.

As shown, the connector element coupling portion 850 and electrodecoupling portion 860 together define a connector element coupling region870 for the electrical and mechanical coupling of a connector element890 (shown in FIG. 13B) to the positive mandrel portion 822. Forexample, both of the connector element coupling portion 850 and theelectrode coupling portion 860 may define a channel 871 within which theconnector element 890 may be located and coupled as generally shown andillustrated in the end view of the mandrel 820 depicted in FIG. 13E.

The connector element coupling portion 850 and the electrode couplingportion 860 may define one or more features that may improve effectivemechanical coupling therebetween. For example, as shown in FIGS.13B-13C, the connector element coupling portion 850 may define twofinger portions 856 and three apertures 858 that are configured toassist in the coupling of a connector element located within the channel871 (e.g., coupled by laser welding, ultrasonic welding, crimping,stamping, pressing, etc.). Likewise, as shown in FIG. 13D (which depictsthe opposite side of the mandrel 820 as FIG. 13C), the electrodecoupling portion 860 may also define two finger portions 896 and threeapertures 898. The finger portions 856, 896 may be deformable, ordeflectable, into the channel 871 to contact a connector element locatedtherein (e.g., to provide pressure to the connector element, to form aninterference fit, etc.). Although this embodiment defines two fingerportions 856, 896 and three apertures 858, 898, it is to be understoodthat this embodiment or any of the other embodiments described hereinmay define one or more finger portions and/or one or more aperturessimilar to the finger portions 856, 896 and apertures 858, 898,respectively. In at least one embodiment, the finger portions 856, 896may be deformed, or deflected, into the channel 871 before, or prior to,a connector element being located therein (e.g., the finger portions856, 896 may be biased to a position within the channel 871, etc.). Assuch, when a connector element is positioned inside the channel 871, thefinger portions 856, 896 may contact, or grasp, the connector element.

In at least one embodiment, the finger portions 856, 896 may not bedeformed, or deflected, into the channel 871 before a connector elementis located therein. In this embodiment, after a connector element hasbeen located inside the channel 871, the finger portions 856, 896 may bedeflected, or deformed, towards the connector element to contact, orgrasp, the connector element to provide improved effective mechanicalcoupling between the connector element coupling portion 850 and/or theelectrode coupling portion 860 and the connector element. For example,the finger portions 856, 896 (or tab portions) may be deflected (e.g.,stamped) into the channel 871 and into contact with the connectorelement 890.

The apertures 858, 898 may be used to, e.g., provide fluid conductionpathways, welding sight lines (e.g., line-of-sight access for a laserweld), expand/thermal growth areas, etc. Further, the apertures 858, 898and the finger portions 856, 896 may be formed in the connector elementcoupling portion 850 and electrode coupling portion 860 before or afterthe connector element coupling portion 850 and the electrode couplingportion 860 are coupled together. In at least one embodiment, theapertures 858, 898 and the finger portions 856, 896 are formed by lasercutting, stamping, punching, etc.

As shown in FIGS. 13A & 13D, the electrode coupling portion 860 mayfurther define one or more electrode coupling regions 872, 882. Morespecifically, the electrode coupling regions 872, 882 of the electrodecoupling portion 860 may define planar, or flat, surfaces 864, 884,respectively, for the coupling of an electrode thereto (e.g., coupled bylaser welding, ultrasonic welding, crimping, stamping, pressing, etc.).

The electrode coupling portion 860 may further define a pair of tabportions 862 and the connector element coupling portion 850 may alsofurther define a pair of tab portions 852 that extend out of the ends(e.g., top and bottom ends) of the positive mandrel portion 822. In atleast one embodiment, the tab portions 852, 862 may be used to provideadditional coupling surfaces to provide effective mechanical coupling toone or more battery assembly features such as one or more insulatorportions, casings, polymer portions, etc.

In this embodiment depicted in FIGS. 13A-13E, the connector elementcoupling portion 850 may be generally planar (e.g., other than thechannel 871 formed in the connector element coupling portion 850). Forexample, the sides of the connector element coupling portion 850 may notinclude bends similar to the bends 761, 763 described herein withreference to FIG. 12D. Instead, only the electrode coupling portion 860may be bent such that it wraps around the generally planar connectorelement coupling portion 850. Further, although space is shown in FIG.13E between the connector element coupling portion 850 and the electrodecoupling portion 860, at least a portion of each of the connectorelement coupling portion 850 and the electrode coupling portion 860 maybe positioned adjacent either other to provide coupling therebetween.

In at least one embodiment, the positive and/or negative mandrel portionof an exemplary mandrel may include a single material. Such a singlematerial may be configured to be coupled to the electrode. For example,the single material may be aluminum, which may be similar to theelectrode material. As such, to provide effective coupling to aconnector element, which may be formed of a different material than thesingle material, a bimetal connector element 900 may be used as depictedin FIG. 14.

The bimetal connector element 900 may include a core 902 and a cladding904. The cladding 904 may cover some or the entire core 902. Asdepicted, the cladding 904 covers a portion of the core 902 leaving anexposed portion 906. The cladding 904 may be formed of the same materialas the positive and/or negative mandrel portion of an exemplary mandrel.For example, if the mandrel portion includes aluminum, then the cladding904 may include aluminum. Further, the core 902 may include a differentmaterial than the cladding 904. In at least one embodiment, the core 902may include titanium. The exposed portion 906 of the core 902 may be theportion of the connector element 900 that may extend outside of abattery assembly (e.g., through an insulator, through a top cover, andthrough a ferrule of a battery assembly, etc.) to be connected to anoutside device.

Another exemplary mandrel 1020 and portions thereof is depicted in FIGS.15-17. The exemplary mandrel 1020 may include a positive mandrel portion1022 and a negative mandrel portion 1024 arranged along axis 1008. Inthis embodiment, the positive mandrel portion 1022 is different than thenegative mandrel portion 1024 (e.g., for illustrative purposes), and assuch, will be described separately. Although the positive mandrelportion 1022 is different than the negative mandrel portion 1024 in thisembodiment, in other embodiments, the positive mandrel portion 1022 andthe negative mandrel portion 1024 may be substantially the same. FIGS.15A-15D depicted the exemplary mandrel 1020, FIGS. 16A-16B depict theconnector element coupling portion of the negative mandrel portion 1024of the exemplary mandrel 1020, and FIGS. 17A-17B depict the electrodecoupling portion of the negative mandrel portion 1024 of the exemplarymandrel 1020. In other words, only portions of the negative mandrelportion 1024, namely the connector element coupling portion andelectrode coupling portion are depicted in FIGS. 16A-16B and 17A-17B,respectively, while the entire exemplary mandrel 1020 is depicted inFIGS. 15A-15D.

As shown, the positive mandrel portion 1022 is wider (e.g., a directionperpendicular to the axis 1008) than the negative mandrel portion 1024,e.g., for manufacturability, to provide electrode coupling regions onopposite sides of the mandrel, etc. In other embodiments, the positivemandrel portion 1022 may be substantially the same size as or smallerthan the negative mandrel portion 1024.

The positive mandrel portion 1022 may be similar to the positive mandrelportion 822 of the exemplary mandrel 820 of FIGS. 13A-13E. For example,the positive mandrel portion 1022 may include a connector elementcoupling portion 1050 and an electrode coupling portion 1060electrically and mechanically coupled to each other. Further, each ofthe connector element coupling portion 1050 and the electrode couplingportion 1060 may include tab portions 1052, 1062, respectively,configured for coupling to additional electrode assembly elements suchas, e.g., one or more insulator portions, casings, etc.

The tab portions 1052, 1062 may also define various features to assistin the coupling of the positive mandrel portion 1022 to additionalelectrode assembly elements and/or features. For example, the tabportions, 1052, 1062 may define apertures 1053 extending through theconnector element coupling portion 1050 and/or the electrode couplingportion 1060. The apertures 1053 may allow a flowable material such asadhesive, insulative material, a polymer, etc. to flow through theapertures 1053 and harden in the apertures 1053 to mechanically couplethe flowable material to the positive mandrel portion 1022. Further, theapertures 1053 may be configured to receive various battery assemblyelements such as protrusions, bolts, etc.

The negative mandrel portion 1024 depicted in FIGS. 15A-15B includes aconnector element coupling portion 1070 and an electrode couplingportion 1080 coupled together. The connector element coupling portion1070 defines a connector element coupling region 1072 for the couplingof a connector element (e.g., coupled by laser welding, ultrasonicwelding, crimping, stamping, pressing, etc.) such as a feedthrough pin.The connector element coupling portion 1070 is constructed, or formed,such that the connector element coupling region 1072 providesintermittent or broken contact to a connector element along a length ofthe connector element coupling region 1072.

Further, as shown more clearly in FIGS. 16A-16B, the connector elementcoupling portion 1070 includes a plurality of alternating fold portions1074. The fold portions 1074 are spaced apart from one another toprovide intermittent, or broken, contact with a connector elementlocated proximate the connector element coupling region 1072 (e.g.,along a length thereof). Spaces between the fold portions 1074 areindicated by arrows 1077 in FIG. 16A. Further, the fold portions 1074may alternate to contact opposing, or diametric, sides of a connectorelement when the connector element is located in the connector elementcoupling region 1072. The fold portions 1074 may alternate betweencontacting a top portion and a bottom portion of a connector elementfrom a first end 1026 to a second end 1028 of the mandrel 1010 as shownin FIGS. 16A-16B. More specifically, top fold portions 1075 may beconfigured to contact a top portion of a connector element and bottomfold portion 1076 may be configured to contact a bottom portion of theconnector element. In this way, the fold portions 1074 may provideopposing forces (as indicated by arrows 1079 in the cross sectional viewof the negative mandrel portion 1024 in FIG. 15 D taken across line1010-1010′ depicted in FIG. 15A) configured to compress a connectorelement therebetween to, e.g., maintain effective mechanical coupling tothe connector element.

When the connector element coupling portion 1070 and the electrodecoupling portion 1080 are coupled together, the bottom fold portions1076 may extend through openings 1082 and slot 1084 of the electrodecoupling portion 1080 as shown in FIG. 15B, which may assist in thecoupling of the connector element coupling portion 1070 and theelectrode coupling portion 1080. For example, the bottom fold portions1076 located in the openings 1082 may restrict movement between theconnector element coupling portion 1070 and the electrode couplingportion 1080.

The bottom fold portions 1076 and the top fold portion 1075 may also becompressed, or pinched, inwardly (e.g., in the same directions as thearrows 1079 of FIG. 15D) by the electrode coupling portion 1080 tofurther assist in the coupling between the connector element couplingportion 1070 and the electrode coupling portion 1080. For example, theperimeters of the openings 1082 and the slot 1084 may contact the bottomfold portions 1076 and the top fold portions 1075 to provide compressiontherebetween.

A front view and a perspective view of the electrode coupling portion1080 are depicted in FIGS. 17A-17B, respectively. As shown, theelectrode coupling portion 1080 defines a slot 1084 and a plurality ofopenings 1082 for receiving the fold portions 1074 of the connectorelement coupling portion 1070. In other words, the slot 1084 and theplurality of openings 1082 may be configured to hold the connectorelement coupling portion 1070 therebetween.

Yet another exemplary mandrel 1120 and portions thereof are depicted inFIGS. 18-20. The exemplary mandrel 1120 may include a positive mandrelportion 1122 and a negative mandrel portion 1124. In this embodiment,the positive mandrel portion 1122 is different than the negative mandrelportion 1124 (e.g., for illustrative purposes), and as such, will bedescribed separately. Although the positive mandrel portion 1122 isdifferent than the negative mandrel portion 1124 in this embodiment, inother embodiments, the positive mandrel portion 1122 and the negativemandrel portion 1124 may be substantially the same. FIGS. 18A-18D depictexemplary mandrel 1120, FIG. 19 depicts the connector element couplingportions of the exemplary mandrel 1120, and FIG. 20 depicts theelectrode coupling portions of the exemplary mandrel 1120. In otherwords, only portions of the exemplary mandrel 1120, namely the connectorelement coupling portions and electrode coupling portions, are depictedin FIGS. 19 and 20, respectively, while the entire exemplary mandrel1120 is depicted in FIGS. 18A-18D.

The negative mandrel portion 1124, however, may be similar to thenegative mandrel portion 1024 of the exemplary mandrel 1020 depicted inFIGS. 15-17. For example, the connector element coupling portion 1170 ofthe negative mandrel portion 1124 may include a plurality of alternatingfold portions 1174 similar to the plurality of alternating fold portions1074 of the connector element coupling portion 1070 depicted in FIGS.15-17. The fold portions 1174 may define a connector element couplingregion 1128 (e.g., an intermittent or broken contact channel). Theelectrode coupling portion 1180 of the negative mandrel portion 1124may, however, include a single aperture 1182 for receiving every otheralternating fold portion 1174 of the connector element coupling portion1170 as shown in FIGS. 18C & 20. Further the electrode coupling portion1180 may also define a channel 1184 located at both ends of theelectrode coupling portion 1180. The channel 1184 may be configured toreceive at least a portion of a connector element to be coupled to thenegative mandrel portion 1124.

The positive mandrel portion 1122 may include a connector elementcoupling portion 1150 and an electrode coupling portion 1160. Thepositive mandrel portion 1122 may define a connector element couplingregion 1126. The connector element coupling region 1126 may be formed byone or both of the connector element coupling portion 1150 and theelectrode coupling portion 1160.

For example, the connector element coupling portion 1150 may define afirst set of coupling fingers 1152 (as shown in FIG. 19) and theelectrode coupling portion 1160 may define a second set of couplingfingers 1162 (as shown in FIG. 20) to, e.g., form at least a portion ofthe connector element coupling region 1126. As shown in FIG. 18B, thefirst set of coupling fingers 1152 and the second set of couplingfingers 1162 may be spaced apart from one another to form intermittent,or broken, contact with a connector element along a length of theconnector element coupling region 1126. In other words, the couplingfingers 1152, 1162 may provide an intermittent or broken contact channelfor receiving a connector element. Spaces between the coupling fingers1152, 1162, are indicated by arrows 1163 in FIG. 18B. In other words,the first and second set of coupling fingers 1152, 1162 may providenon-continuous contact with a connector element.

Further, the first set of fingers 1152 may provide a downward force on aconnector element while the second set of fingers 1162 may provide anupward force on a connector element as shown by the arrows 1165 in thecross sectional view of the exemplary mandrel 1120 taken across line1110-1110′ depicted in FIG. 18D.

Similar to the negative mandrel portion 1124, the electrode couplingportion 1160 may also define a channel 1164 configured to receive atleast a portion of a connector element to be coupled to the positivemandrel portion 1122.

This disclosure has been provided with reference to illustrativeembodiments and is not meant to be construed in a limiting sense. Asdescribed previously, one skilled in the art will recognize that othervarious illustrative applications may use the techniques as describedherein to take advantage of the beneficial characteristics of theapparatus and methods described herein. Various modifications of theillustrative embodiments, as well as additional embodiments of thedisclosure, will be apparent upon reference to this description.

What is claimed:
 1. A mandrel for an electrode assembly comprising: apositive mandrel portion comprising: a connector element coupling regionconfigured for coupling the positive mandrel portion to a connectorelement, wherein the connector element coupling region comprises a firstconductive material, and an electrode coupling region electricallycoupled to the connector element coupling region and configured forcoupling the positive mandrel portion to an electrode, wherein theelectrode coupling region comprises a second conductive materialdifferent than the first conductive material; and a negative mandrelportion spaced apart from the positive mandrel portion, wherein thenegative mandrel portion comprises: a connector element coupling regionconfigured for coupling the negative mandrel portion to a connectorelement, wherein the connector element coupling region comprises a firstconductive material, and an electrode coupling region electricallycoupled to the connector element coupling region and configured forcoupling the negative mandrel portion to an electrode, wherein theelectrode coupling region comprises a second conductive materialdifferent than the first conductive material.
 2. The mandrel of claim 1,wherein, for at least one of the positive mandrel portion and thenegative mandrel portion, at least a portion of the electrode couplingregion is positioned adjacent to at least a portion of the connectorelement coupling region to mechanically couple the connector elementcoupling region and the electrode coupling region.
 3. The mandrel ofclaim 1, wherein, for at least one of the positive mandrel portion andthe negative mandrel portion, the connector element coupling regiondefines a mating region configured to mate with a mating region definedby at least a portion of the electrode coupling region to mechanicallycouple the connector element coupling region and the electrode couplingregion.
 4. The mandrel of claim 3, wherein the mating region of theconnector element coupling region defines an opening configured toreceive at least a portion of the mating region of the electrodecoupling region.
 5. The mandrel of claim 1, wherein, for at least one ofthe positive mandrel portion and the negative mandrel portion, theelectrode coupling region is formed by depositing the second conductivematerial.
 6. The mandrel of claim 1, wherein, for at least one of thepositive mandrel portion and the negative mandrel portion, the connectorelement coupling region defines a connector element channel configuredfor receiving a connector element to be coupled therein, and wherein theelectrode coupling region comprises at least a planar surface forcoupling an electrode thereto.
 7. The mandrel of claim 1, wherein themandrel further comprises a removable portion removably coupled to bothof the positive mandrel portion and the negative mandrel portion.
 8. Themandrel of claim 1, wherein the second conductive material of theelectrode coupling region of the positive mandrel portion is differentthan the second conductive material of the electrode coupling region ofthe negative mandrel portion.
 9. The mandrel of claim 1, wherein, for atleast one of the positive mandrel portion and the negative mandrelportion, the first conductive material comprises titanium and the secondconductive material comprises aluminum.
 10. The mandrel of claim 1,wherein, for at least one of the positive mandrel portion and thenegative mandrel portion, the connector element comprises the firstconductive material and the electrode comprises the second conductivematerial.